Is he lying to me?

The other day my partner went to the bathroom to shower and get ready for work as always. My son who was upstairs said he felt sick and needed the bathroom. My partner was in there and I became aware that he didn't turn the shower on for a good 15 minutes. I eventually messaged him and said 'what are you doing, bashing one out, son feels sick'. I don't care if he actually was but i was a bit annoyed just due to the circumstances of needing the bathroom, plus I have a baby that was needing feeding etc while I was with my son. My partner has a watch that messages go to and he had his phone. When he came down he seemed a bit avoidant and left. His phone said he opened the message at around 8am shown by the blue ticks but feel he would have read it before that. I was just expecting something along the lines of 'oh shut up, what's up with son' or along those lines but he just completely ignored me all day which we don't do unless we have an argument-which is never about this. About 7 hours later I messaged him again and said 'take that as a yes then lol, followed by info he needed for the vet". He replied of course yea couldn't be anything else could it, nothing I love more than banging one out before a day working with the boys' (colleagues). He then just said he was on eBay and sent me a screenshot of an order. I said I was a little confused as to why I'd been ignored all day and said I didn't get why it would take 15 minutes to buy a universal remote but ok. It's a busy house of 6 so the bathroom is always needed in the morning anyway! I want to highlight I don't care if he doing this in there- but I really feel like he's lying about it and the lying is annoying me. He seemed to be really defensive and annoyed. I dont really understand why he wouldn't have just said 'no I was shopping on eBay what's up with son' in the first place. And I don't understand why I was just ignored for the entire day. I said it was weird to be ignored and he just ignored that too

Is he lying to me?
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